As is hitherto known, while rotating a photosensitive drum of an image transfer unit, an electrophotographic image forming apparatus transfers a toner deposited on a cylinder surface of the photosensitive drum onto a recording medium such as a paper sheet or an OHP sheet. The electrophotographic image forming apparatus then heats the toner transferred on the recording medium by a heat roller, and fixes the toner on the recording medium to form an image on the recording medium.
When the recording medium is heated by the heat roller, the part on the heat roller side of the recording medium thermally shrinks. Accordingly, the recording medium tends to bend (curl) in such a manner as to curl around the heat roller.
JP-A-2004-177880 discloses a structure, in which a roller having a curl removing function (which is hereinafter referred to as a curl removing roller) is provided just behind the heat roller, thereby to remove the curl.
The curl removing roller removes curl in the following manner. The curl removing roller imparts curl in the opposite direction from the direction of the generated curl to the recording medium, and thereby cancels out the already generated curl.